Removable Anchor from Petzl

The COEUR PULSE is a 12 mm removable anchor made of stainless steel that can be installed and removed very simply and rapidly, without tools. The locking function limits the risk of involuntary removal.

They only do imperial sizes (3/4 and 1″), not for metric holes, so we never imported them. Charles does own one.
Petzl tell us availability will for the 12mm version only be September, the date above is outdated.
(12 mm is the standard hole size for our local 10 mm expansion or glue-in bolts).

Something along the lines of this might be even better than titanium at preventing our rock from looking like Swiss cheese in the long term (think of the impact of hundreds or thousands of years of bolting)